Under current CDMA2000 architecture, a mobile station (MS) may exchange packetized information to devices (e.g., desktop computers, laptops, and the like) coupled to a public IP network, such as the Internet. In particular, a mobile station (e.g., cellular phone, PDA, laptop, and the like) sends a wireless communication to a base station (BS) where the information is received by a radio network controller (RNC), down-converted, and packetized by a packet control function (PCF) entity at the RNC.
The service provider (SP) may utilize a private IP network having multiple packet data serving nodes (PDSN), which route the packetized data to the public IP network. The PCF sends the data to a PDSN using a generic routing encapsulation (GRE) tunnel, where a point-to-point protocol (PPP) connection is terminated at the PDSN.
One problem with the current CMDA2000 architecture is that the CDMA2000 architecture makes data services device orientated, rather than user orientated. In particular, one responsibility of the PCF is to compute which PDSN is used to send the MS's connection, i.e., to form a GRE tunnel. Each PCF maintains a configuration table of all the current PDSN's available in the service provider's (SPs) private network, and then determines a particular PDSN to use. In the PDSN configuration table the PDSNs are locally numbered from 0 to N−1 in ascending order of PDSN 11) addresses, where N is the total number of entries in the table. For initial PDSN assignment and reselection, the PCF determines which PDSN to use for a particular mobile station by a PDSN selection algorithim: PDSN No.=(truncated MS IMSI) modulo N, where the MS IMSI is a unique number for each mobile station. That is, the PDSN No.=(truncated MS IMSI) modulo N. For example, if a MS having an IMSI value of 7053 is in communication with a PCF, and there are eight PDSN's in the SP's private network (N=8), then 7053 modulo 8=5. It is noted that the PCF uses the remainder (5) as an index or correlation value pertaining to one of the N PDSNs. In the example above where the PDSNs are numbered between zero (0) and N−1, the sixth PDSN (PDSN No.=5) is utilized by the PCF to terminate an IP tunnel therebetween.
As such, it is important that the configuration tables of all the PCFs match, since disparities may result in the selection of the wrong PDSN, which may result in loss of particular services provided by a particular PDSN or session termination due to PCF handoff. Moreover, the PCF has no knowledge of the capabilities of the PDSNs, or the service requirements of the mobile user when the PCF selects a PDSN. As such, a PCF may connect to a PDSN having limited service capabilities.
Various PDSN's provide different services, such as virtual private networks (VPN), prepaid services, and the like. As such, a subscriber of data services may only utilize such services by connecting to a PDSN capable of such services. For example, a subscriber who has VPN services may not be able to utilize the VPN services if such subscriber uses a mobile station (e.g., PDA) of a third party. That is, that third party may not subscribe to the same type or level of services from the service provider. As such, the third party's particular PDA may not have authorization to connect to a PDSN having VPN services. Therefore, the subscriber is limited to services from their own particular mobile station.
A third problem with the current architecture includes a lack of load balancing among the multiple PDSNs. That is, the data service provider cannot guarantee that the sessions are distributed evenly, which may result in bandwidth shortages, and loss of connectivity.
A fourth problem occurs when a PDSN fails, and all data session anchored to the failed PDSN terminate. The only possible recovery is to reinitiate the data sessions from the MS's and then redirect them to a working PDSN. However, by doing so, all mobile users' current data sessions that are being handled by the PDSN will terminate. In addition, the simple IP address of the MS may change. Moreover, if a PCF can reach only one PDSN, no recovery is possible in instances where that one PDSN fails.
Another problem occurs during roaming by the MS between two PCF's. In particular, a data session built on simple IP terminates when the PCFs are disjoint at the PDSN level; the PCFs are not disjoint, but one or more PCFs have incorrectly configured PDSN table entries; or if the PDSN is at full load capacity and cannot accept a new connection. Therefore, there is a need to provide improved data services for mobile station subscribers.